The sliding tracks for industrial computer casing have been developed for a long time. In one prior art, a track has a rear support frame and a front supporting frame which is received in the rear supporting frame. Each supporting frame has a retaining portion at the ends far away from another supporting frame. A positioning unit passes through a first and a second retaining portion so as to be fixed to one end of a casing of a server. The front and rear supporting frames are installed with a first and a second connecting portion so as to adjust the whole length of the whole structure. Thus the tracks of the server casing can be assembled with objects of different sizes.
Furthermore in another prior art, two sliding bodies are disclosed. One body has a sliding space for assembling another body. One end of each body is assembled with a connecting portion which can be assembled into a casing. An extension portion of one body is assembled to a casing of different size which has a design like above mentioned structure.
However, above mentioned prior arts have complicated structures and are difficult in adjustment.